Hemispherical resonator gyros are known and are often used as rate sensors as part of inertial reference units (IRU's) in spacecraft and as part of inertial measurement units (IMU's) in aircraft and land vehicles. Much like a wine glass which rings when it is struck, the hemispherical-resonator gyro is a precisely machined glass hemispherical shell mounted within a protective case that is induced to ring through the use of electrostatic forces. A rotation of the vehicle containing the gyro will cause the location of the ringing pattern to rotate within its case. The angle of the pattern rotation can then be detected within the gyro to determine the rotation of the vehicle. This rotation information is then provided to a processor which uses it to determine the orientation of the vehicle in inertial space. The ringing vibration is so minute that it creates virtually no internal stress and fatigue effects in the gyro, leading to its unmatched reliability.
Miniaturization of components is an important issue for many applications, and is especially important for spacecraft and other vehicles where size and weight are at a premium. Ideally the miniaturization of a component should be accomplished with no degradation in performance.
Thus, there is a need for miniaturization of hemispherical-resonator gyros without loss of performance.